ehrhart



Oct. 15, 1929. E. N. EHRHART l mamon oF REFIMNG SUGAR Filed March 4, 1926 2 IN V N TOR. BY j Z ATTORNEY Patented Oct. 15, 1929 UNITED STATES ATNT OFFICE EUGENE N. EHRI-IART, OF NEW ORLEANS, LOUISIANA, ASSIGNOR TO JOHN J. NAU'GLE,

OF BROOKLYN, YORK i METHOD 0F REFNIllG SUGLR Application filed March Il,

My present invention relates to methods of treating,l saccharine fluids, particularly for the refining of sugar juices and melts, syrups, affiliations and other Lrun-off, and molasses, and aims to devise methods of the general character specified which are simple and convenient to practice, vwhich result in certain conveniences in operation permittino' equivalent economies in the practice of the methods of the present invention, and which result in savings in fuel and labor charges which are important items in the cost of refining saccharine fluids, particularly of the classes referred to above. The methods of the present invention possess other conveniences in operation and result in other economies in part pointed out in detail hereinafter and in part obvious to those skilled in the art to which the present invention relates. TWhile not limited thereto, my present invention finds `aarticularly successful application in connection With the refiningl of such saccharine fluids as sugar juices and melts, syrups, affinations and other runeoffs, and molasses by the use of activated vegetable carbone, particularly the highly activated carbon known to the trade SachaL In the accompanying specication l shall describe several. illustrative embodiments of the methods of the present invention. lt is, however, to be clearly understood that my invention is not limited to the specific forms thereof herein described for purposes of illustration only.

Before describing the aforesaid illustrat've embodiments of the methods of the present invention in detail, it may be desirable bri ,fly to point out the factors in the economies of the refining of saccharine fluids. such as sugar juices, and melts, syrups, aflinations and run-oils, and molasses, especially by the use of activated vegetable carbon, towards which the methods of the present invention are particularly directed in the interest of improvements and equivalent economies in operation. One of the largest items of expense in the refiningof saccharine fluids, such as sugar juices and melts.y syrups, allinations and other run-offs, and molasses, is the. fuel item. The fuel item is, in fact, generally 1926. Serial NO. 92,102.

about equal in importance to the labor item, which latter item is only exceeded in the usual case by the expense of the sugar package item. This fuel item may be reduced by filteringr the affiliations and certain other runoffs, thereby reducing the amount of steam required by the boil-backs, or such fuel item may be r aluced by sending` to the vacuum pans a filtered melt of increased density.

lfnother item of expense in the refiningof encchariue fluids, such as sugar juices and melts, syrups, aflinations and other run-offs and molasses, is the handling and revivifying` of the vegetable carbon used. @f course, Where the lcarbon is such that it cannot be revivilied, this item of eXpense becomes very considerable and in some instances may indeed become prohibitive. @n the other hand where the carbon may be revivilied, in the Well known ease of the highly activated vegetable carbon knoivn to the trade as Sechi/ii, WlAL l is fully described and which is claimed in the copendinnr application of John (l. Ser. No. 633,640, filed April 2l, 1923, Lled Method of treating` earbonaceous terial in an electric furnace or the like, used in the Suchar process, this expense becomes a relatively moderate one but is still non-negligible, beingdependent upon the quantity of carbon required for the purification. Any economically sound system of utilising; the Sucher or other activated vegetable carbon or other puriAU filtering medium Which Will reduce the quantity of car* bon required for the treatment of a .fen unit of Weight of sugar solids contain ed in the saccharine fluids being; treated will correspondingly reduce the refining; cost.

Suchai is the name by which is known in the market the highly activated vegetable carbon of great decolorizing, purifying and filtering` powers and which may, after use, be completely revivified With full restoration of its or' al decolorizing, purifying and filtering; pervers by suitable treatment in an elect-ric furnace, Suchai may be prepared by treating leached carbouisced lignin residues or c"leachcr refuse, obtained by carbonizinej the alkaline liquors uerivcd as a b vproduct 'from the manufacture of Wood pulp a year, or a resulting saving of 24s.?

creased filterability and purity and increased density may be treated With a predetermined amount ot a more active or less spent Sucher or other vegetable carbon, or other purifying and filtering medium, and finally the batch oli saccharine fluid thus obtained may have its density further increased by the addition of still another portion of sugar solids or of relatively concentrated syrup and the batch ol' still higher degree of decolorination and iilterability and of still higher density thus obtained may be treated with a predetermined Weight of virgin or relatively highly activated Suchar or other carbon or other purifying medium.

In other Words, I apply the principles of multiple density filtration in accordance with the methods of the present invention on the counter-current basis ot' operation, regiulatw ing the densities of successive batches ol saccharine fluid until the linally purified melt is obtained, to obtain batches of successively increasing densities and successively increasing degrees of purity, decolorization and i'ilterability, increased densities corresponding' generally to increased decrees ot purity, decolorization and filterability, obtaining this result by successive treatments With batches of carbon of increasing degrees oi' activation. In accordance with the principles ofthe present invention, the spent or partially spent Suchar or other vegetable carbon or other purifying filtering` medium obtained from the filters after treating` one batch ot' saccharine fluids in accordance with the principles of the present invention is used lor the treatment of another batch of saccharine fluids of lower density and lower degree of purity than the batch Which it has just been used to treat, unless the carbon is so spent that it should be sent, in the case of Sucher, for example, to the revivifier.

One immediate result of this inode of procedure is the reduction of the amount of steam required by the evaporating pans in the formation of refined sugar, in the case, for example, Where sugar melts are being` treated in accordance with the principles of the present inven cn. In such a case, for ei:- ainple, if the melt Was tilt-ered and decelerizetL so as to be supplied to the pans at an increased density, corresponding to about lo lleauni or about 7.60 Brif: higher than is feasible under the present practice, vitli crude oil at three and one-half cents per `trallon, a saving` would be oiii'ected el $57,000 per annum in a rednery a capacity of live hundred (500) tons of sugar a day, calculating on a basis of three hundred SGO) d Y 1 cents per ton of sugar produced. This saving; of cents per ton of sugar produced cific example being;` given, would ur any installation irrespective of its s foregoing economies result in from the fact that using a given quantity of Suchai or any other vegetable carbon or other filtering purifying medium, any ordinary saccharine iiuid Will filter more readily after it is totally or partially prei'iltered.

Before describing one specific example carrying the principles of the present invention into efliect, it may be desirable to chicle date further the principles and considerations on Which the methods of the present invention are based. Using a given purifying and filtering medium, such as Suchar, for example, a prefiltered sugar melt of a density of, say 29o Beaume, which has already been pretiltered by the use of a given Weight of semi-exhausted Sucher, could have its density increased, say, to about 33 Beaum by the addition of more original raW sugar being purified. The sugar melt of increased density could then be readily filtered through the same Weight of SuchaiJ7 in a less eX- haustcd or virgin condition as the unpreiiltered melt ot' lovver density first referred to. These same considerations hold true even to more marked degree of saccharine fluids of lower degrees of purity, such as molasses, lain-offs"7 and syrups, or any other saccharine liquors, as Well as for the saccharine liquors customarily lrnovvn as melts, degrees BriX differing.

A carbon after having` been used to filter and decolorize a sugar-containing liquor still has some capacity to filter and decoloriae the same kind of a solution and, to a lesser degree, to deeolorize the same general liind of liquor. Having` already been used for such a purpose initially, its ability during,` its subsequent use for a similar purpose is substantially reduced. In some instances, as with allinations or even lower grades of saccharine fluids, the practical value of such a spent carbon is questionable unless unnecessarily large quantities of carbon are used or liquors are handled quite low in density. However, even in such cases, and certainly in the cases pre "iously discussed, the use of such semi-exhausted or almost completely spent carbon or other filtering medium for preliltration is advisable because to do so reduces the total quantity of carbon needed to purify a given quantity of sugar. Accordingly, the cost of handling, revivifying and replacing" the carbon, together With the total cost of the installation, is correspondingly reduced.

In applyino,` the principles of the present invention, it is desirable to so standardize the volumes and densities of the saccharine fluids treated in successive stages, in accordance with the principles of the present invention, that substantially similar Weights of almost completely spent, semi-exhausted and virgin Sucher or other carbon or other filtering medium may be used for the corresponding batches to be treated. This facilitates the sugar melts, such as syrups, run-offs, molasses, etc., substantially the same mode of procedure may be carried out, except, of course, that lower' densities of solutions are used in the case of liquors of increasingly lower grades. For instance, the first liquor filtered with semi-exhausted carbon may be of a density ranging from about l2 to about 25 Beaume, while the second batch of liquor filtered through virgin carbon may correspond to from about 22 to about 350 Beaum.

The foregoing constitute illustrative embodiments of the methods of the present invention. The advantages of the methods of the present invention, particularly as exemplified in the foregoing illustrative embodiments of the same, have already been pointed out earlier in this specification and may be briefly summarized as follows: By means of the application of the methods of the present invention, as exemplified in the foregoing illustrative embodiments of the same, numerous economies in steam for evaporation purposes and in the fuel required to generate such steam, as well as in boiler and power house capacities, may be effected. Such economies result in diminished overhead charges and render possible an appreciable saving per ton of refined sugar or other saccharine product, which saving adheres to each ton of sugar or other saccharine produce produced in accordance with the principles of the methods of the present invention, and is not dependent upon the size or capacity of the plant in tons of sugar, per day, produced therein. By means of the principles of the present invention, particularly as exemplified in the foregoing illustrative embodiments of the invention, many economies in the handling and manipulation of the Suchar or other vegetable carbon or other filtering and 'purifying medium are rendered possible. hese economies permit aroportional sai/ings in carbon and hand ing expenses. Other advantages of the methods of the present invention will be obvious to those skilled in the art to which the present invention relates.

It may here be stated that the expression sugar juices or melts, syrup, affinations or other run-offs7 or molasses, includes, first, sugar juices whether derived from sugar cane or sugar beets; includes also sugar melts obtained by the melting or dissolving of sugar in water, whether the sugar is unwashed raw, washed raw or other sugar; and that the term syrup includes not only afiinations or other run-offs, but syrups obtained from other sources or by other means, including also all refinery liquors having a sugar content.

The drawing submitted herewith contains a single figure and comprises a diagram in the nature of a flow sheet exemplifying the process. The legends on the drawing malte clear the different stages of the process so sugar containing solution of a certain density with a filtering of low purifying power, and thereafter adding to the filtrate thus obtained unfiltered values of the same material, whereby a solution is obtained of greater density and partially filtered.

3. rlhe method of refining sugar containsolutions which comprises filtering av 2 solution of a certain oensity with a fil ing agent which has already been used for filtering a sugar containing solution, and thereafter adding to the filtrate thus obtained unfiltered values of the saine material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and partially ltered.

Ll. rlhe .method of refining sugar containing solutions, which comprises filtering a containing solution of a certain density with an activated carbon of a relatively low degree of activation, and thereafter adding to the filtrate thus obtained unfiltered sugar values of the same material as in said filtrate in an amc-unt calculated to substantially increase its density, wiereby a solution is obtained of greater density which is partially filtered and partially decolorized.

5. The method of refining sugar containing solutions which comprises filtering a sugar containing solution of a certain density with an activated carbon which has alreac y been used for filtering a sugar containsolution, and thereafter adding to the filtrate thus obtained unfiltered values of the saine material as in said filtrate in an amount calc dated to substantially increase its density, whereby a solution is obtained of great-er density which is partially filtered and partially decolorized.

6. The method of refining sugar containing solutions which comprises filtering a sugar containing solution with a filtering agent which has already been used to filter a sugar containing solution of the same nature but of higher density, and thereafter adding to the filtrate thus obtained unfiltered values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and partially filtered.

sugar containii 7. The method of refining sugar containing solutions which comprises filtering a sugar containing solution with an activated carbon which has already been used to filter a sugar containing solution of the same nature but of higher density, and thereafter adding to the filtrate thus obtained unfiltered values of the saine material as in said filtrate in an amount calculated to substantially in crease its density, whereby a solution is obtained of greater density which is partially ltered and partially decolorized.

8. The method of refining sugar containing solutions, which comprises filtering a s containing solution of' a certain oenlity, ing to the filtrate thus obtained vaines of saine material as in said filtrate in an calculated to substantially increase its C whereby solution is obtained of greater density and partially filtered, and thereafter filtering the resulting rartially filter solution of increased density.

9. The methol oi" refining su solutions, which comprises containing solution of a certain densitv u filtering` agent of low filtering power, r l tothe filtrate thus obtained values of the :ame material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of' greater density and partially vfiltered, and thereafter filtering the resulting` partially filtered solution of increased density with a filtering agent of relatively high filtering power.

10. The methol of refining sugar containing' solutions, which comprises filtering a containing solution of a certain density with an activated carhon of a relatively loiv degree of activation, adding to the filtrate `thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained ot greater density and partially filtered and partially decolorized, and thereafter filtering the resulting partially filtered and partially deec-lorized solution of increased density with an activated carbon of' a relatively high degree of activation.

11. rllhe method of refining sugar containing solutions which comprises filtering a sugar Containing solution of a certain density with a filtering agent which has already been used to iilter a sugar containing solution, adding to the ltrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of grea ir density and partially filtered, and thereafter filtering the resulting Jartially filtered solution of increased density with a filtering agent of maximum decolorizing power.

19. rEhe method of refining sugar containing solutions which comprises a sugar containing solution, of certain density with an activated carbon which has already been Yiig/31,237*

used to filter a sugar containing solution, add ing to the filtrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and partially filtered and partially decolorized, and thereafter filtering the resulting partially filtered and partially decolorized solution of greater density with an activated carbon of maximum decolorizing power.

13. rElie method of refining sugar containsolutions which comprises filtering a sugar containing solution with a filtering agent which has alreadv been used to filter a sugar containing solution of' the saine nature but of higher density, adding to the filtrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and par tially filtered, and thereafter filtering the resulting partially filtered solution of increased density with a filtering agent which has olready been used to filter a solution of' the same nature but of higher density.

le. rifhe method of refining sugar containing solutions which comprises filtering a sugar containing solution with an activated carbon which has already been used to filter a sugar containing solution of the saine nature but of higher density, adding to the filtrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and partially filtered and decolorized, and thereafter filtering the resulting partially filtered and partially decolorized solution of increased density with an activated carbon which has already been used to filter a solution of the same nature but of higher density.

15. rlhe method of refining sugar containing solutions which comprises filtering a sugar containing solution with a filtering agent which has already been used to filter a sugar containing solution of the saine nature but of higher density, adding to the filtrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and partially filtered, and thereafter filtering the resulting partially filtered solution of increased density with a. filtering agent of maX- imuin decolorizing power.

16. The method of refining sugar containing solutions which comprises filtering a sugar containing solution with an activated carbon which has already been used to filter a sugar containing solution ot the same nature but of higher density, adding to the filtrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and titl partially filtered and decolorized, and thereafter filtering the resulting partially filtered and partially decolorized solution of increased density with an activated carbon of maximum decolorizing power.

17. The method of refining sugar containing solutions which comprises filtering` a sugar containing solution of a certain density with a filtering agent which has already been used to filter a sugar containing solution, adding to the ltrate values of the same material as in said filtrate in an amount calculated to substantially increase its density, whereby a solution is obtained of greater density and partially ltered, and thereafter filtering the resulting partially filtered solution of increased density ivith a filtering agent of relatively higher power which has already been used to filter a sugar, syrup, aflinations or other run-oils, or molasses solution.

18. The method of refining sugar containing solutions, which comprises filtering a sugar containing solution of a certain density with an activated carbon which has already been used to filter a sugar containing solution, adding to the filtrate thus obtained values of the same material as in said filtrate in an amount calculated to substantially in crease its density, whereby a solution is obtained of greater density and partially filtered and partially decolorized, and thereafter filtering the resulting partially filtered and partially decolorized solution of increased density with an activated carbon of f relatively high power which has already been used to filter a sugar containing solution.

In testimony, whereof, I have signed in name to this specification this 16th day of February, 1926.

E. N. EHRHART. 

